# A mark is a fragment of music with an optional fitness score assigned.
# Marks are collected into annotations which comment on a voice.
class HeadMusic::Style::Mark
  attr_reader :start_position, :end_position, :placements, :fitness

  def self.for(placement, fitness: nil)
    new(placement.position, placement.next_position, placements: [placement], fitness: fitness)
  end

  def self.for_all(placements, fitness: nil)
    placements = [placements].flatten.compact
    return [] if placements.empty?

    start_position = placements.map(&:position).min
    end_position = placements.map(&:next_position).max
    new(start_position, end_position, placements: placements, fitness: fitness)
  end

  def self.for_each(placements, fitness: nil)
    placements = [placements].flatten
    placements.map do |placement|
      new(placement.position, placement.next_position, placements: placement, fitness: fitness)
    end
  end

  def initialize(start_position, end_position, placements: [], fitness: nil)
    @start_position = start_position
    @end_position = end_position
    @placements = [placements].flatten.compact
    @fitness = fitness || HeadMusic::PENALTY_FACTOR
  end

  def code
    [start_position, end_position].join(" to ")
  end
  alias_method :to_s, :code
end